An examination of the relationship between aggregate soundness on laboratory pavement performance measures.

摘要

The relationship between an aggregate's durability and performance in pavements do not always align. Soundness testing is an indicator of an aggregate's susceptibility to break down as a result of environmental factors. Currently, the Sodium Sulfate Soundness test, AASHTO T 104, is the main indicator used by the Arkansas State Highways and Transportation Department (AHTD). For many aggregates this test will suffice; however, when performed on some limestone or dolomite aggregates there is a discrepancy on whether the test represents the durability of the aggregate. This is in part because of the lack of precision in the results that the Sodium Sulfate Soundness test returns (1, 2, 3). Multiple labs can produce very different results allowing one lab to accept an aggregate while another will reject it. However, just because one lab rejects an aggregate does not necessarily mean that the aggregate will have poor performance in the field.;In this research, eight (8) different aggregate types were used to compare aggregate soundness tests to aggregate laboratory performance tests involving HMA and PCC. The aggregates consisted of two carbonate aggregates (limestone and dolomite), and a syenite aggregate (treated as the control). Soundness tests run include: AASHTO T 104 Sodium Sulfate Soundness Test, AASHTO T 327 Micro-Deval, AASHTO T 103 Aggregate Freeze-Thaw, Vacuum Saturation, and Aggregate Freeze-Thaw by Deep Freeze. HMA and PCC laboratory performance tests run include: The Evaluator of Rutting and Stripping in Asphalt, AASHTO T 283 Resistance of Compacted Hot Mix Asphalt to Moisture-Induced Damage, PCC Cylinder Strength, ASTM 666 Resistance of Concrete to Rapid Freezing and Thawing, and Freeze-Thaw by Deep Freeze. Each aggregate soundness test was compared using linear regression to other soundness tests as well as to each performance test.;It was found that AASHTO T 283 was the best indicator of aggregate laboratory performance when relating to soundness tests. The use of ERSA outputs, while not relating to any specific soundness test, could be used to adequately rank aggregate quality. No PCC laboratory performance data was found to relate to any of the soundness tests, suggesting that mineralogy plays a less important role in the mixing of concrete. Further, in determining a test to replace the Sodium Sulfate Soundness test, the use of AASHTO T 103 and Micro-Deval are suitable suggestions, however, further research needs to be performed on the topic to confirm these results.